London: He's spent four years in international limbo waiting to play for Australia, is the grandson of a former Fiji president, the nephew of a coup leader and has a family story filled with heartache and controversy.

But Henry Speight says playing his first game for the Wallabies is his chance to change the meaning of his family's name and put a smile on the faces of kids with cancer in Fiji.

The softly spoken and polite Fijian-born winger is the newest face in the Wallabies squad and he carries a quiet determination to change the perception of the Speight name in Australia and Fiji.

The "Bro with the Fro" also wants to raise $10,000 for the Walk On Walk Strong Foundation - a charity raising awareness for childhood cancer - to make his late mother and cousin proud.

His uncle George Speight led the Fijian coup in 2000, ousting the then prime minister and taking government MPs hostage for weeks.

"I can't change the course of what's happened. It's history now. The name George Speight will be synonymous with a coup leader. I can't change that," Speight said.

"I can change the perspective of a generation coming through now that when they hear the Speight name they associate it with a rugby player or anything political. That's my objective.

"But to be honest, there are bigger things than my name. This journey I'm on and doing stuff for these kids going through a tough time.

"I met a group of 15 kids two years ago, the oldest 16 and the youngest one-and-a-half. Half of that group are not with us any more. That's more important to me than how people view my name or see me as a rugby player."

Speight will play his first game for Australia against the Barbarians at Twickenham on Sunday morning Australian time, ending four years stuck in international uncertainty, thanks to an IRB eligibility bungle.

His first press conference as a Wallaby went for 28 minutes, covering topics from his uncle George and his grandfather, the late president Ratu Josefa Iloilo, to his siblings' struggles to get visitor visas to Australia.

It left little time to talk about his upcoming mouth-watering clash against the Honey Badger, Nick Cummins, in what Speight dubbed "a battle of the hairdos".

Grandfather Iloilo convinced Speight to choose Australia over a potential career in New Zealand four years ago in the hope that he could forge a career with the Brumbies and Wallabies.

Iloilo became a very controversial figure, mainly for abolishing the constitution in 2009 which entrenched the rule of dictator Frank Bainimarama.

Iloilo died in the days before Speight's Super Rugby debut, but he will be close to the 26-year-old's heart at Twickenham.

"[Iloilo] said I'd be silly not to consider [the Brumbies]. There are certain people who aren't with me any more, but they're with me in spirit. I just want to do them proud and live up to expectations that they had," Speight said.

The ACT Brumbies' flyer's rugby skill is obvious. But when he injured his hamstring and missed 11 weeks and then Ewen McKenzie quit as Test coach, Speight thought his Wallabies dream had all but disappeared.

Speight will shave his afro when he returns to Australia in December.

He started growing it for 100 days as part of Fijian tradition in memory of his cousin, Malachi, who died of cancer last year. Speight's mother, Adi Litia, died of cancer when he was just eight.

"To be able to change a kid's life or make their recovery after chemo or radiation a bit better with a resource centre, that would mean more to me than trying to convince people about my name," Speight said.

"I hope they get a feeling of happiness and for the kids, to have an association with a Wallabies player fighting the same cause. If they see me playing and it puts a smile on their face, that makes me happy."

Speight has been long regarded as one of the best wingers in Australia. But the IRB put up an international road block for his eligibility case because he hadn't spent three consecutive years in Australia.

At times his passion and dream wavered as the IRB quashed his Wallabies hopes and then the Australian government rejected visa applications for his brother and sister to visit Canberra.

His older brother Sam is in the British army and hopes to be in the crowd on Saturday.

"Regardless if it's a Test or not, it makes no difference. It's a chance to put on the gold jersey and I have a lot of respect for the people who have gone before. I guess I am [representing two countries]."